Plain English Meaning

Shaped so the air slides past it cleanly instead of getting churned up and slowing it down.

Full Definition

Shaped so that air flows smoothly around an object with minimal turbulence and drag. A streamlined body aligns with the relative wind so that airflow follows its contours rather than separating into disturbed, turbulent flow.

Context Anchor

Seen when describing aircraft shape, control-surface position, and any part that is designed to reduce air resistance in flight.

Derivation

From 'stream' (a smooth flow of fluid) and 'lined' (shaped along that line). The word literally describes a shape that follows the line of the flowing stream of air.

Why Pilots Care

Streamlined parts reduce drag, which improves , , and the responsiveness of .